ART. 22 TERTIARY FOSSIL PLANTS FROM ARGENTINA — BERRY 7 



country. If the map is correct the geography would favor warm cur- 

 rents from the Atlantic and the land barrier would temper Antarctic 

 influences. We know that there was a corresponding submergence 

 of the Chilean littoral at this time, and there is no evidence of high 

 mountains on the site of the Andes, which is also negatived by the 

 floral evidence of equability and humidity. 



DESCRIPTIONS OF SPECIES 



Order POLYPODIALES 



Family CYATHEACEAE 



Genus ALSOPHILA R. Browne 



ALSOPHILA ANTARCTICA Christ (?) 



Alsophila antarctica Christ in Dusen, Schwed. Siidpolar-Exp., vol. 3, Lief. 3, 

 p. 14, pi. 3, fig. 11, 1908. 



This species was described for Dusen's account of the Tertiary 

 plants from Seymour Island, Antarctica, by Professor Christ of 

 Basel, who considered it most like the existing Alsophila feeana and 

 A. corcovadensis of southern Brazil. A single fragment in the pres- 

 ent collection is identical with the illustration of the Seymour Island 

 type except that it is slightly smaller, and as it is sterile it might as 

 well be considered to represent the genus Polypodiurn. 



Occurrence. — Two and one-half leagues above emboucheur of the 

 canyon of Rio Nirihuao into the basin of Lago Nahuel Huapi, Terri- 

 tory of Rio Negro. 



Ple»iotype.—C2it. No. 37851, U.S.N.M. 



Family POLYPODIACEAE 



Genus ADIANTUM Linnaeus 



ADIANTUM PATAGONICUM. new species 



Plate 1, Figures 5-7 



There are more or less complete specimens of four pinnules in the 

 collection, the largest and most complete being the one shown in 

 Figure 5; a second is only about half the size of the former. Pin- 

 nules stipitate, nearly orbicular in outline, divided nearly symmetri- 

 cally by narrow pointed sinuses into four principal (two terminal 

 and two lateral) lobes and the lateral lobes more or less bisected. 

 The distal margins are undulate. Terminal sinus widest and deep- 

 est, extending three-fourths of the distance to the base of the lamina, 



